Open AccessLower ant Diversity on Earth Mounds in a Semi-Arid Brazilian Ecosystem: Natural or a Sign of Degradation?
Author(s) -
Karine S. Carvalho,
Marcos Augusto Ferraz Carneiro,
Ivan Cardoso do Nascimento,
Amartya Saha,
Emilio M. Bruna
Publication year - 2016
Publication title -
sociobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.378
H-Index - 38
eISSN - 2447-8067
pISSN - 0361-6525
DOI - 10.13102/sociobiology.v63i4.1171
Subject(s) - biodiversity , ecosystem , ecology , arid , species richness , vegetation (pathology) , habitat , deforestation (computer science) , litter , biology , environmental science , agroforestry , medicine , pathology , computer science , programming language
Natural earth mounds in many ecosystems harbor higher biodiversity than surroundings because they provide greater habitat heterogeniety. However, in the semi-arid Caatinga ecosystem of NE Brazil, natural mounds have much less vegetation and leaf litter with lower biodiversity as compared to the surrounding lowlands. The following hypotheses were tested: (i) low vegetation cover on the mounds results from highly compacted and leached soils as compared to adjacent lowlands and (ii) low vegetation cover reduce ant populations and diversity because of limited foraging and nesting resources. This study was carried out in four mound fields. Adjacent lowlands were found to have twice as many ant individuals as the mounds along with higher ant species richness and diversity. The high resistance of the mound soil to root penetration and low pH could be the main reason for the difference in diversity between mound and adjacent lowlands. Further investigations are needed to infer whether this low diversity on mounds is a natural feature, or a result of ongoing environmental degradation in the Caatinga, whereupon deforestation leads to hardened and compacted soils.